Kochi | Veteran CPI leader and the party's state secretary Kanam Rajendran died at a private hospital here on Friday following cardiac arrest, party sources said.
He was 73.
The senior leader of the Communist Party of India has been undergoing treatment at the hospital for multiple ailments including heart and kidney related issues and diabetes.
His right foot was recently amputated to contain the spread of an infection due to diabetes and had applied for three months leave from the party responsibilities due to health reasons.
Though the leader had expressed confidence of a speedy recovery, his health condition suddenly worsened this evening following a cardiac arrest, they said.
The news of the unexpected demise of the veteran leader came as a shock for everyone cutting across political parties in the state.
His death comes at a time Chief Minister Pinarayi Vijayan and other ministers are taking part in the Nava Kerala outreach programme in this district.
The CM and his cabinet colleagues visited the hospital after wrapping up the scheduled programmes and paid their last respects.
Popularly known as Kanam in the party and political circles, Rajendran had been serving as the state secretary of the CPI for three consecutive terms since 2015.

He was serving as the national executive and central secretariat member of the party.
A two-time MLA, well-known trade unionist and an accomplished organiser, Kanam Rajendran was considered as one of the strongest leaders of the ruling Left Democratic Front after Chief Minister Vijayan.
Known for his strong political stands which he adopted during the time of various controversies that hit the first and second LDF governments under Vijayan, Rajendran was described by political observers as a corrective force in the Left front.
He was also a leader who showed keenness to maintain the unity of the LDF, in which CPI is the second largest coalition partner.
Born at Kanam in Kottayam district in 1950, Rajendran entered politics at a tender age and became the state secretary of the CPI's youth wing All India Youth Front (AIYF) at 23.
He rose quickly through the ranks to become CPI's state secretariat member at the age of 25.
Rajendran made significant interventions in the trade union sector after becoming the state secretary of the Kerala State Trade Union Council and the national vice president of the trade union outfit AITUC.
He represented Vazhoor constituency in the state assembly twice--1982 and 1987.

The leader unsuccessfully contested in three Assembly elections later.
He is survived by wife and son and daughter.
Meanwhile, condolences poured in from various quarters over the sudden demise of the CPI state secretary.
Governor Arif Mohammed Khan, Chief Minister Pinarayi Vijayan, CPI national secretary D Raja, CPI (M) state secretary M V Govindan, KPCC Chief K Sudhakaran, BJP state president K Surendran were among those who extended their condolences.
Vijayan, in a detailed condolence message, termed Rajendran's death as "shocking".
"We lost a unifying force of the Left front through the demise of Kanam Rajendran... His contribution to strengthen the communist movement, the unity of the working class, to safeguard the democratic institutions, are priceless," he said.
Recalling him as leader who voiced to uphold the rights of the working class, the CM said he was keen on maintaining the good relationship between the CPI(M) and the CPI.
"He left us at a time when the cooperation of the Left parties is most essential," he said
The CM also said that he, personally, had numerous emotional memories with him in the decades-long political life.
He was friend and a comrade, Vijayan added.
According to CPI sources, the leader's mortal remains would be taken to Thiruvananthapuram on Saturday morning and kept there for public homage.
Later, the remains would be taken to his native village in Kottayam, where the cremation would be held on Sunday.